How to set up a workflow for multiple project environment

We’re a museum with many exhibitions and special projects going at once. We need a project management system that supports gantt, calendar, and displays priority at top level for each project. I have set up several ways but have not gotten a workable solution. I need to be able to view all projects in single line form with their priority and status visible, and I need to be able to open the list of sub items for each project and assign them to calendar or gantt. How do I do this?